/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// This file makes some assumptions about the versions of macOS.
// We are assuming that the major, minor and bugfix versions are each less than
// 256.
// There are MOZ_ASSERTs for that.

// The formula for the version integer is (major << 16) + (minor << 8) + bugfix.

#define MACOS_VERSION_MASK 0x00FFFFFF
#define MACOS_MAJOR_VERSION_MASK 0x00FFFFFF
#define MACOS_MINOR_VERSION_MASK 0x00FFFFFF
#define MACOS_BUGFIX_VERSION_MASK 0x00FFFFFF
#define MACOS_VERSION_10_0_HEX 0x000A0000
#define MACOS_VERSION_10_7_HEX 0x000A0700
#define MACOS_VERSION_10_8_HEX 0x000A0800
#define MACOS_VERSION_10_9_HEX 0x000A0900
#define MACOS_VERSION_10_10_HEX 0x000A0A00
#define MACOS_VERSION_10_11_HEX 0x000A0B00
#define MACOS_VERSION_10_12_HEX 0x000A0C00
#define MACOS_VERSION_10_13_HEX 0x000A0D00
#define MACOS_VERSION_10_14_HEX 0x000A0E00
#define MACOS_VERSION_10_15_HEX 0x000A0F00
#define MACOS_VERSION_10_16_HEX 0x000A1000
#define MACOS_VERSION_11_0_HEX 0x000B0000

#include "nsCocoaFeatures.h"
#include "nsCocoaUtils.h"
#include "nsDebug.h"
#include "nsObjCExceptions.h"

#import <Cocoa/Cocoa.h>

int32_t nsCocoaFeatures::mOSVersion = 0;

// This should not be called with unchecked aMajor, which should be >= 10.
inline int32_t AssembleVersion(int32_t aMajor, int32_t aMinor, int32_t aBugFix)
{
  MOZ_ASSERT(aMajor >= 10);
  return (aMajor << 16) + (aMinor << 8) + aBugFix;
}

int32_t nsCocoaFeatures::ExtractMajorVersion(int32_t aVersion)
{
  MOZ_ASSERT((aVersion & MACOS_VERSION_MASK) == aVersion);
  return (aVersion & 0xFF0000) >> 16;
}

int32_t nsCocoaFeatures::ExtractMinorVersion(int32_t aVersion)
{
  MOZ_ASSERT((aVersion & MACOS_VERSION_MASK) == aVersion);
  return (aVersion & 0xFF00) >> 8;
}

int32_t nsCocoaFeatures::ExtractBugFixVersion(int32_t aVersion)
{
  MOZ_ASSERT((aVersion & MACOS_VERSION_MASK) == aVersion);
  return aVersion & 0xFF;
}

static int intAtStringIndex(NSArray *array, int index)
{
  return [(NSString*)[array objectAtIndex:index] integerValue];
}

void nsCocoaFeatures::GetSystemVersion(int &major, int &minor, int &bugfix)
{
    major = minor = bugfix = 0;

    NSString* versionString = [[NSDictionary dictionaryWithContentsOfFile:
                                @"/System/Library/CoreServices/SystemVersion.plist"] objectForKey:@"ProductVersion"];
    NSArray* versions = [versionString componentsSeparatedByString:@"."];
    NSUInteger count = [versions count];
    if (count > 0) {
        major = intAtStringIndex(versions, 0);
        if (count > 1) {
            minor = intAtStringIndex(versions, 1);
            if (count > 2) {
                bugfix = intAtStringIndex(versions, 2);
            }
        }
    }
}

int32_t nsCocoaFeatures::GetVersion(int32_t aMajor, int32_t aMinor, int32_t aBugFix)
{
  int32_t macOSVersion;
  if (aMajor < 10) {
    aMajor = 10;
    NS_ERROR("Couldn't determine macOS version, assuming 10.7");
    macOSVersion = MACOS_VERSION_10_7_HEX;
  } else if (aMajor == 10 && aMinor < 7) {
    aMinor = 7;
    NS_ERROR("macOS version too old, assuming 10.7");
    macOSVersion = MACOS_VERSION_10_7_HEX;
  } else {
    MOZ_ASSERT(aMajor >= 10);
    MOZ_ASSERT(aMajor < 256);
    MOZ_ASSERT(aMinor >= 0);
    MOZ_ASSERT(aMinor < 256);
    MOZ_ASSERT(aBugFix >= 0);
    MOZ_ASSERT(aBugFix < 256);
    macOSVersion = AssembleVersion(aMajor, aMinor, aBugFix);
  }
  MOZ_ASSERT(aMajor == ExtractMajorVersion(macOSVersion));
  MOZ_ASSERT(aMinor == ExtractMinorVersion(macOSVersion));
  MOZ_ASSERT(aBugFix == ExtractBugFixVersion(macOSVersion));
  return macOSVersion;
}

/*static*/ void
nsCocoaFeatures::InitializeVersionNumbers()
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  // Provide an autorelease pool to avoid leaking Cocoa objects,
  // as this gets called before the main autorelease pool is in place.
  nsAutoreleasePool localPool;

  int major, minor, bugfix;
  GetSystemVersion(major, minor, bugfix);
  mOSVersion = GetVersion(major, minor, bugfix);

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

/* static */ int32_t
nsCocoaFeatures::macOSVersion()
{
  // Don't let this be called while we're first setting the value...
  MOZ_ASSERT((mOSVersion & MACOS_VERSION_MASK) >= 0);
  if (!mOSVersion) {
    mOSVersion = -1;
    InitializeVersionNumbers();
  }
  return mOSVersion;
}

/* static */ int32_t
nsCocoaFeatures::macOSVersionMajor()
{
  return ExtractMajorVersion(macOSVersion());
}

/* static */ int32_t
nsCocoaFeatures::macOSVersionMinor()
{
  return ExtractMinorVersion(macOSVersion());
}

/* static */ int32_t
nsCocoaFeatures::macOSVersionBugFix()
{
  return ExtractBugFixVersion(macOSVersion());
}

/* static */ bool
nsCocoaFeatures::OnYosemiteOrLater()
{
  return (macOSVersion() >= MACOS_VERSION_10_10_HEX);
}

/* static */ bool
nsCocoaFeatures::OnElCapitanOrLater()
{
  return (macOSVersion() >= MACOS_VERSION_10_11_HEX);
}

/* static */ bool
nsCocoaFeatures::OnSierraOrLater()
{
  return (macOSVersion() >= MACOS_VERSION_10_12_HEX);
}

/* static */ bool 
nsCocoaFeatures::OnHighSierraOrLater() 
{
  return (macOSVersion() >= MACOS_VERSION_10_13_HEX);
}

/* static */ bool 
nsCocoaFeatures::OnMojaveOrLater() 
{
  return (macOSVersion() >= MACOS_VERSION_10_14_HEX);
}

/* static */ bool 
nsCocoaFeatures::OnCatalinaOrLater() 
{
  return (macOSVersion() >= MACOS_VERSION_10_15_HEX);
}

/* static */ bool
nsCocoaFeatures::OnBigSurOrLater()
{
  // Account for the version being 10.16 (which occurs when the
  // application is linked with an older SDK) or 11.0 on Big Sur.
  return ((macOSVersion() >= MACOS_VERSION_10_16_HEX) ||
          (macOSVersion() >= MACOS_VERSION_11_0_HEX));
}

/* static */ bool
nsCocoaFeatures::IsAtLeastVersion(int32_t aMajor, int32_t aMinor, int32_t aBugFix)
{
    return macOSVersion() >= GetVersion(aMajor, aMinor, aBugFix);
}